Optical treatment methods

ABSTRACT

A treatment system and method includes use of a chemical facilitator to provide a result-effective event against one or more negative therapeutic effects related to exposing to a light output a skin portion including a condition treatable in whole or in part with light. In one exemplary embodiment for skin treatment including tattoo removal, perfluorodecalin is used to inhibit or resolve whitening, for example to speed a laser therapy session.

RELATED APPLICATIONS

This application is a continuation of, and relates and claims priorityto, U.S. patent application Ser. No. 13/436,087, filed Mar. 30, 2012,now U.S. Pat. No. 8,394,359, issued on Mar. 12, 2013; which relates andclaims priority to: the U.S. provisional patent application Ser. No.61/528,130 entitled “System and Method for the Treatment of VascularLesions,” filed on Aug. 26, 2011, by Michael P. O'Neil; and the U.S.provisional patent application Ser. No. 61/595,065 entitled “System andMethod for Tattoo Removal,” filed on Feb. 4, 2012, by Michael P. O'Neil.

FIELD OF THE INVENTION

The invention relates generally to systems and methods for skin therapyprocedures, and more particularly in one exemplary embodiment, tosystems and methods including chemical use in one or more treatmentprocesses or steps associated with skin tattoo procedures (e.g., tattoolightening, part or full tattoo removal), which hereafter may be moregenerally referred to as “tattoo procedures” or a “tattoo procedure.”

In another aspect, the invention more particularly relates to tattooprocedures including use of a chemical to promote treatment.

In another aspect, a chemical delivery process or step may occur (i)before, (ii) after, and/or (iii) concurrently with, use of an emitter orlight-generating device for a tattoo procedure (e.g., a laser, a lamp(such as a flash lamp as used in an intense pulsed light (IPL) device orapplication), or other light output device).

In another aspect, the chemical may be a topical chemical.

In another aspect, the chemical may include a fluorocarbon.

In another aspect, the chemical may include a non-hydrocarbonsurfactant.

In another aspect, the chemical may include a fluorosurfactant.

In another aspect, the chemical may include perfluorodecalin.

In another aspect, the invention more particularly may relate to asystem or method comprising a sterile device including a chemical.

In another aspect, the sterile device may be a single use device, andthe single use device may include a topical chemical.

In another aspect, the sterile device may include one or more of: afluorocarbon; a non-hydrocarbon surfactant; a fluorosurfactant; andperfluorodecalin.

The above-listed aspects are not necessarily limiting on the invention,nor is one or more of the listed aspects necessarily required in aninvention embodiment. The aspects are set forth above without limitationsimply to describe the field of the invention.

BACKGROUND OF THE INVENTION

There has been a long felt need for a treatment system and method fortattoos, for tattoo procedures, etc. that is effective without theundesirable side effects of the prior art. There is no universallyaccepted tattoo treatment. Laser phototherapy (photothermolysis) isperhaps the best treatment regimen available to date for tattoolightening and removal.

Physicians often use laser phototherapy involving lasers operating at avariety of wavelengths and power and fluence levels. Some physiciansprefer Q-switched Nd:YAG lasers operating at 1064 nm. Others prefertypically Q-switched alexandrite lasers operating at 755 nm. Stillothers prefer dye lasers operating in the visual portion of thespectrum, or, for example, frequency doubled Nd:YAG lasers operating at532 nm, sometimes described as “KTP lasers”, KTP being the crystal whichdoubles the frequency of the laser. Many other laser types andwavelengths have been used in tattoo procedures as well.

While some favorable treatment results have been achieved, no treatmentregimen is without problems. For example, full thickness burns thatleave permanent scars have been observed as adverse events followinglaser phototherapy. Thus, although various devices and techniques havebeen used, none so far have proven significantly effective.

One reason for problems or adverse events in tattoo treatment may relateto the unpredictable nature of the thermal conversion of oxyhemoglobin(HbO₂) and deoxyhemoglobin (RHb) into methemoglobin (metHb). metHb has amuch higher optical absorption relative to HbO₂ or rHb in the nearinfrared (NIR) portion of the spectrum thus facilitating thermal runawayonce conversion has started. This unpredictable, pseudo-instantaneousconversion is of particular concern in connection with the use of NIRlight (i.e., the NIR portion of the spectrum (e.g., around 1064 nm)),which is otherwise desirable for use since NIR light penetrates moredeeply into the treatment site than visible light. Use of NIR light thusmay permit tattoo treatment to a greater depth, which may result in abetter outcome as more of the area or volume including the tattooportion to be treated can be treated at one time. Prior systems andmethods simply are not significantly effective in controlling thethermal conversion of HbO₂ and RHb into metHb.

Another reason for adverse events in tattoo treatment using priorsystems and methods may be the unpredictable nature of the treatmentsite. At all wavelengths, including the isosbestic point between HbO₂and RHb (approximately 810 nm), the optical absorption of the blood inthe vessels can significantly change in the course of a Q-switched orsimilar laser pulse. In practical terms, a pulse that is perfectly welltolerated in one location or tattoo portion may induce adverse effects(e.g., burning, scarring, pain, hypopigmentation, hyperpigmentation) inanother nearby location or portion. This is because the localscattering, absorption, and/or other properties proximate to the tattoomay change from site to site, which contributes to the uncertainty ofthe extent of photothermal conversion of HbO₂ and RHb into metHb fromsite to site. Blood treated in the vasculature at one location proximatethe tattoo may thermally convert into metHb to a different extent thanblood in the vasculature in a different location proximate the tattoo.

A somewhat similar yet separate reason for adverse events in tattooprocedures using prior systems and methods may relate to an unacceptablylow level of treatment repeatability. Unwanted uncertainty and resultsstem from the unpredictability associated with optical and physiologicaldifferences across patients. Every patient, every tattoo, etc. isdifferent. An effective set of treatment parameters in one patient mayunexpectedly cause an adverse event in another patient with a seeminglyidentical tattoo or condition. Prior systems and methods simply lack adesired robustness in that they are not significantly effective incontrolling factors, e.g., the thermal conversion of HbO₂ and RHb intometHb, across individual patients in a treatment group.

One problem, then, in a particular aspect may be viewed as an optical“runaway” effect. Prior systems and methods may be unattractive becausethis adverse event may occur, for example, as the laser used intreatment is gradually increased in power and/or fluence. Asphoto-thermal conversion of one or more hemoglobin species into metHboccurs, suddenly a small change in one or more laser operatingparameters or one or more treatment conditions may have a grossly largereffect due to the new presence of metHb. As one example, variations inpressure that the physician applies to a laser hand piece may inducevarying degrees of exsanguination, altering the optical properties of atreatment area, and confounding predictability of photo-thermalconversion. Purpura can result from this effect as well.

Differences in the types of tattoos treated also results in problematicoutcomes. Certain tattoo colors (e.g., yellow, green, brown) typicallyare difficult to treat as compared to other colors (e.g., black) usingprior approaches. There is no significantly effective prior system andmethod applicable to the wide variety of tattoo colors (includingdifficult to treat colors).

Another problem associated with prior art tattoo procedures is thatoften such procedures are messy. Typically, debris is ejected from atreatment site, e.g., during laser use. The debris may be solids,liquids, gases, aerosols, and/or other forms of ejecta. Also, with somepatients, a treating clinician may be exposed as a result to anunacceptable risk of exposure, e.g., to HIV, hepatitis-C, and/or otherinfectious diseases. There is no significantly effective prior systemand method to help control such ejecta and reduce such adverse risks.

Another problem associated with prior art tattoo procedures may stemfrom treatment side effects. By way of example, during a laser treatmentsession, exposure of a treatment area to a laser output may create oneor more conditions within the treatment area that tend to reduce theeffectiveness of subsequent laser exposures. One example of such sideeffects is a “whitening” of the area treated.

During tattoo treatment, a “whitening” reaction typically occurs, asevidenced by the formation of bubbles, e.g., in the dermis. Thewhitening reaction typically occurs immediately upon first laserexposure, with results of the reaction remaining during and aftersubsequent laser exposures in the same session. The whitening reactionmay include, result in, or be caused by, the generation of bubbles orother factors, e.g., due to rapid heating or energy transfer associatedwith laser exposure, due to laser-induced shock waves, due tomicroscopically “explosive” cell or other reactions, due to two photonprocesses (e.g., associated with use of a picosecond or faster laser),etc.

The “bubbles” associated with whitening may be micro-cavitation bubblesand/or other events and/or circumstances capable of having similar orother negative therapeutic effects, e.g., attenuation of light, lightscattering, etc. For convenience only, and without limitation, suchbubbles and/or other events and/or circumstances shall be referred toherein individually and collectively as a “bubble” or “bubbles.”

Bubbles generally may be located in an area or volume including aportion of the dermis, although other locations are possible too. Thebubbles generally may be located in an area or volume including aportion of skin. Heating may be localized, and/or may produce orotherwise cause or promote localized bubble generation. Typically,tissue, skin, tattoo pigment, the dermis portion, etc. are heated duringtreatment.

It has been observed that a whitening reaction may fade over abouttwenty minutes or more following the last laser exposure. Such fadingmay be evidenced by the dissolving of bubbles including gas, or by otherfactors associated with bubble reduction. Resolution of the whiteningreaction may be caused at least in part by the cooling of one or moreheated portions.

Whitening is problematic at least in part because the presence ofbubbles in the treatment area from a first laser pass may attenuate orweaken the delivery of light in one or more subsequent laser passes. Forinstance, light impinging on bubbles may scatter in multiple directions,including away from the treatment area. Thus, bubble presence reduceslight therapy effectiveness.

Typically, clinicians in tattoo procedures may avoid in part some of theadverse consequences of whitening simply by waiting for the unwantedwhitening condition to resolve naturally. Where such a therapy sessionincludes, for example, four laser passes, the total session treatmenttime (i.e., length of session) may equal about 60-80 minutes or more.

Treatment time, then, often is quite problematic. Typically, prior arttattoo treatment includes, among other things, a single treatmentsession including multiple (e.g., up to four) laser exposures to atreatment area, with an interval of twenty minutes or more between laserexposures. See, e.g., Kossida et al, Optical tattoo removal in a singlelaser session based on the method of repeated exposures, J. Am. Acad.Dermatology 2012 feb 66(2): 271-7. Such lengthy treatment time oftenposes significant problems for patients and clinicians alike. Bothclinicians and patients generally would prefer shorter treatment timesas compared to such extended periods. This is especially true whenmultiple treatment sessions are required over a period of months toachieve desired results.

Thus, what is needed is an improved method and system for tattootreatment that helps predictably and effectively treat tattoos whilecontrolling, reducing, minimizing, and/or eliminating one or more of:(i) the optical “runaway” effect, (ii) system operating or treatmentparameter uncertainties, and (iii) one or more other disadvantages thatmay be associated with prior art systems and methods for treatingtattoos (e.g., whitening, attenuation, lengthy treatment times, etc.).

SUMMARY

The present disclosure provides a skin therapy procedure system andmethod.

In one exemplary embodiment, a tattoo procedure comprising laser therapyincluding chemical use provides for shorter treatment times. Forexample, and without limitation, a single tattoo treatment session fortattoo lightening or removal may last only a few minutes, and/or a timeinterval between successive laser passes may be less than about twentyminutes.

Other benefits and advantages of the present disclosure will beappreciated from the following detailed description.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a tattoo on skin.

FIG. 2 is an exemplary representation of a treatment area comprising askin portion including the tattoo of FIG. 1.

FIG. 3 is a cross-sectional view of the skin portion and tattoo shown inFIG. 2, along the line 3-3 in FIG. 2, as viewed from an angleperpendicular to the cross-sectional plane in the direction indicated bythe arrows at line 3-3 in FIG. 2.

FIG. 4 is a flow chart depicting an exemplary prior art tattoo removalmethod including a “WAIT” step.

FIG. 5A is an illustration of an exemplary laser pass treating thetattoo shown in FIG. 3

FIG. 5B is an illustration of the tattoo shown in FIG. 3 immediatelyfollowing the exemplary laser pass illustrated in FIG. 5A.

FIG. 5C is an illustration of the tattoo portion shown in FIG. 5B afterabout twenty minutes or more of waiting in accordance with prior tattooprocedures.

FIG. 6 is a flowchart of an exemplary embodiment of a light therapysession including use of a chemical facilitator.

FIG. 7 is a flowchart of another exemplary embodiment of a light therapysession including use of a chemical facilitator.

FIG. 8 is an illustration of an exemplary embodiment including use ofperfluorodecalin against whitening of the type shown by way of examplein FIG. 5B.

FIG. 9A is an illustration of an exemplary embodiment including use ofperfluorodecalin for the exemplary tattoo shown in FIG. 3.

FIG. 9B is an illustration of an exemplary tattoo treatment includingthe exemplary embodiment shown in FIG. 9A.

FIG. 10A is an illustration of another exemplary embodiment includinguse of perfluorodecalin for the exemplary tattoo shown in FIG. 3.

FIG. 10B is an illustration of an exemplary tattoo treatment includingthe exemplary embodiment shown in FIG. 10A.

FIG. 11 is an illustration of the exemplary tattoo shown in FIG. 3following an exemplary treatment including an embodiment of thedisclosure.

FIG. 12A is an illustration of the exemplary tattoo shown in FIG. 3,following an exemplary treatment, including more than one laser pass,and including whitening.

FIG. 12B is an illustration of the exemplary tattoo shown in FIG. 3,following an exemplary treatment, including more than one laser pass,and including use of an exemplary embodiment of the disclosure.

FIG. 13A is an illustration of the exemplary tattoo shown in FIG. 3,following an exemplary treatment, including more than one laser pass,and including use of an exemplary embodiment of the disclosure againstwhitening.

FIG. 13B is an illustration of the exemplary tattoo shown in FIG. 3,following an exemplary treatment, including more than one laser pass,and including use of an exemplary embodiment of the disclosure.

DETAILED DESCRIPTION

Embodiments of the invention and various alternatives are describedbelow. Those skilled in the art will recognize, given the teachingsherein, that numerous alternatives and equivalents exist which do notdepart from the invention. It is therefore intended that the inventionnot be limited by the description set forth herein or below.

One or more specific embodiments of the system and method will bedescribed below. These described embodiments are only exemplary of thepresent disclosure. Additionally, in an effort to provide a concisedescription of these exemplary embodiments, all features of an actualimplementation may not be described in the specification. It should beappreciated that in the development of any such actual implementation,as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but would nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

Further, for clarity and convenience only, and without limitation, thedisclosure (including the drawings) sets forth exemplary representationsof only certain aspects of therapeutic events and/or circumstancesrelated to this disclosure. Those skilled in the art will recognize,given the teachings herein, additional such aspects, therapeutic eventsand/or circumstances related to this disclosure, e.g., additionalelements of the dermis, the tissue, and the tattoo; events occurringwithin the stratum corneum, epidermis, and upper and lower dermalregions; etc. Such aspects related to this disclosure do not depart fromthe invention, and it is therefore intended that the invention not belimited by the certain aspects set forth of therapeutic events andcircumstances related to this disclosure.

FIG. 1 shows an example of a tattoo 10 (i.e., a broken heart) on skin20. A skin portion 30 including the tattoo 10 is shown in FIG. 2. FIG. 3is an exemplary cross section of the skin portion 30 and tattoo 10,taken along the line 3-3 in FIG. 2.

FIG. 4 is a flowchart that illustrates an exemplary prior art tattooremoval laser therapy session. The session includes a method including a“WAIT” step 120. During the treatment session illustrated in FIG. 4, foreach laser pass, a waiting period of about twenty minutes or more may berequired, to allow time for whitening to resolve naturally.

Referring to FIGS. 2 and 3, tattoos may be located in the dermis 70,below a skin surface 40, the stratum corneum 50, and the epidermis 60(i.e., located below the D-E junction 80). The location, shape, andoverall make up of every tattoo is different. FIG. 2 illustrates that,in general, tattoos may typically reside below the D-E junction 80 inthe upper portion of the dermis, and may include a plurality ofphagocytosed cells 90 including pigment. The cells 90 naturally migrateslowly, if at all, over time, giving the tattoo a certain degree ofpermanence.

Although a tattoo may appear to the naked eye to include sharp lines oredges, for most tattoos a closer examination under the skin surfacetypically reveals otherwise. The surfaces and edges of a tattoo may bequite bumpy or rough, due in part to the imprecision associated withtattoo formation. Thus, a tattoo cross section may have a varying depth,as illustrated for example in FIG. 3.

FIG. 3 shows an exemplary cross section of the tattoo of FIG. 2, takenalong the line 3-3, when viewed from an angle that is generallyperpendicular to the cross-section face and in the direction indicatedby the arrows at line 3-3 in FIG. 2. The tattoo 10 as shown in FIG. 3includes a plurality of phagocytosed cells 90. The distribution of suchcells 90 may vary. The volume including the tattoo may include otherfeatures in addition to the phagocytosed cells 90, e.g., an interstitialspace between the cells 90. For clarity and convenience only, FIGS. 2,3, 9A and 10A illustrate an outline of a tattoo portion and phagocytosedcells, and the FIGS. 5A-C, 8, 9B, 10B, 11, 12A-B, and 13A-B illustratethe outline only (although it is and should be understood that suchtattoo portions describe and include the phagocytosed cells and otherfeatures, despite the absence of any express illustration of the same).

The disclosure relates generally to systems and methods includingchemical use in one or more treatment processes or steps associated withskin tattoo procedures (e.g., tattoo lightening, part or full tattooremoval) (which hereafter may be more generally referred to as “tattooprocedures” or a “tattoo procedure”).

In another aspect, the disclosure more particularly relates to tattooprocedures including use of a chemical to promote treatment.

In another aspect, a chemical application process or step may occur (i)before, (ii) after, and/or (iii) concurrently with, use of an emitter orlight-generating device for a tattoo procedure (e.g., a laser, a lamp(such as a flash lamp as used in an intense pulsed light (IPL) device orapplication), or other light output device).

In another aspect, the chemical may be a topical chemical.

In another aspect, the chemical may include a fluorocarbon.

In another aspect, the chemical may include a non-hydrocarbonsurfactant.

In another aspect, the chemical may include a fluorosurfactant.

In another aspect, the chemical may include perfluorodecalin.

In another aspect, the disclosure more particularly may relate to asystem or method including a sterile device including a chemical.

In another aspect, the sterile device may be a single use device, andthe single use device may include a topical chemical.

In another aspect, the sterile device may include one or more of: afluorocarbon; a non-hydrocarbon surfactant; a fluorosurfactant; andperfluorodecalin.

In another aspect, a chemical application process or step may occur (i)before, (ii) after, and/or (iii) concurrently with, use of an emitter ora light-generating device for a tattoo procedure (e.g., a laser, a lamp(such as a flash lamp as used in an intense pulsed light (IPL) device orapplication), or other emitter), wherein the chemical is: (a) a topicalchemical, or (b) not a topical chemical.

In another aspect, the chemical may be a topical chemical including oneor more of: (i) a fluorocarbon, (ii) a surfactant, (iii) afluorosurfactant, and (iv) a non-hydrocarbon surfactant; either alone orin combination.

In another aspect, the topical chemical may include perfluorodecalin.

In another aspect, a tattoo procedure may include one or moreapplications of light from an emitter or light-generating device to askin area including a tattoo. More particularly, in tattoo proceduresincluding two or more light applications, one or more chemicals may beapplied to a skin area including a tattoo (i) before, (ii) after, and/or(iii) concurrent with, each light application. In one aspect, an appliedchemical may include perfluorodecalin and/or one or more otherfluorocarbon compounds. In another aspect, application of a chemical mayinclude a topical treatment of such skin area. In another aspect (e.g.,in another exemplary embodiment), a chemical may be injected under askin surface using one or more needles or another delivery device.

In another aspect, a tattoo procedure may include exposing a skin areaincluding a tattoo portion to: (a) one or more applications of lightfrom an emitter or a light-generating device, wherein the time periodbetween light applications is (i) greater than, (ii) less than, and/or(iii) about equal to, twenty (20) minutes; and (b) a topical chemical.The topical chemical may be perfluorodecalin. Where light applicationsoccur in a single session, one or more of the intervals between skinlight exposures may be substantially less than about twenty minutes.

In general, a light application may include one or more exposures of atreatment area to one or more emitter light outputs, e.g., one or morelaser pulses, lamp pulses, or the like. A treatment area may be exposedto one or more emitter outputs. For example, under circumstances inwhich an emitter output covers only a portion of an intended treatmentarea, multiple outputs may be necessary to obtain full treatment. Thatis, if an emitter output for instance appears relatively small andcircular in shape at the surface of the treatment area, clinicians orothers may use two or more overlapping outputs, which may be fully orpartially overlapping, to treat a larger and/or non-circular tattooarea. Typically, a treatment area may receive or be exposed tosufficient outputs in such manner (e.g., size, placement, strength, timeof exposure, etc.) as to achieve a desired therapeutic result. Forexample, an area may be treated until a desired whitening effect occurs,which may be identified for instance by an observed color change orother result; by achieving a desired evenness of coverage; by achievinga desired completeness of coverage; etc.

For convenience, a group of one or more light applications occurringtogether in a single time period may be referred to herein as a“treatment session” or a “laser session.” Further, and again forconvenience, multiple treatment sessions may be identified based uponthe amount of time between two or more groups of light applications.

In a case where at least one treatment session includes only one lightapplication (i.e., a group of one) or multiple light applications (i.e.,a group of two or more), multiple treatment sessions may be identifiedby the passage of more than about twenty (20) minutes between one lightapplication group and one or more preceding or subsequent lightapplication groups.

By way of example only, and without limitation, a skin area including atattoo may be treated by one or more light applications on a first day(i.e., day 1), and one or more light applications on a second day (i.e.,day 2) that is different from the first day. In such example, thetreatment on day 1 may be regarded as a first treatment session, and thetreatment on day 2 may be regarded as a second treatment session. Day 1and day 2 may be consecutive days, or day 1 and day 2 may be one or moredays, weeks, or months apart.

By way of further example only, and again without limitation, a skinarea including a tattoo portion may be treated by one or more lightapplications during a first period (i.e., period 1), and one or morelight applications during a second period (i.e., period 2) that isdifferent from the first period. In such further example, the treatmentduring period 1 may be regarded as a first treatment session, and thetreatment during period 2 may be regarded as a second treatment session,provided that the time between period 1 and period 2 is greater thanabout twenty (20) minutes. For instance, and without limitation, asingle day would include multiple treatment sessions when period oneoccurs during early morning, and period two occurs during afternoon orevening on the same day. Period 1 and period 2 may be consecutiveperiods spaced more than about 20 minutes apart. Period 1 and period 2also may be spaced days, weeks, or months apart.

In general, multiple treatment sessions may be identified by the passageof an amount of time between groups of light applications that is morethan about twenty (20) minutes; and, in accordance with an exemplaryembodiment of the disclosure, the approximate amount of time of at leastone treatment session including multiple light applications may be lessthan about twenty minutes multiplied by the number of light applicationsin the session.

During tattoo treatment, a “whitening” reaction occurs, as evidenced forinstance by the formation of bubbles, e.g., in the dermis. The whiteningreaction typically occurs immediately upon first laser exposure, withresults of the reaction remaining during and after subsequent laserexposures in the same session. It has been observed that the whiteningreaction and/or its results fade over about twenty minutes following thelast laser exposure, as evidenced for example by the dissolving of gasbubbles. Other factors may cause bubble reduction. The whiteningreaction may include, result in, or be caused by, the generation ofbubbles or other factors, e.g., due to rapid heating or energy transferassociated with laser exposure, laser-induced shock waves,microscopically “explosive” cell or other reactions, two photonprocesses (e.g., associated with use of a picosecond or faster laser),etc. The bubbles may be micro-cavitation bubbles. The bubbles generallymay be located in an area or volume including a portion of the dermis.The bubbles generally may be located in an area or volume including aportion of skin.

A “whitening” or “whitening reaction” in one aspect refers to any eventor combination or sequence of events, alone or in combination, causing anegative therapeutic effect resulting from exposure of a treatment areato a light output (e.g., a laser output). The events, alone or incombination, in sequence or not, may include a chemical reaction (ornot); a physical change (or not); and/or one or more chemical reactions(or not) and physical changes (or not), either alone or in combination.In one aspect, then, this disclosure describes a skin treatment method,including: (a) exposing to a light output a skin portion including acondition treatable in whole or in part with light; and (b) providing anamount of a chemical facilitator sufficient to provide aresult-effective event against a negative therapeutic effect, e.g.,related to step (a), of performing the skin treatment method, related tothe skin treatment method, etc. The result-effective event can be asingle event, and/or a sequence or combination of events, and mayinclude a chemical reaction (or not); a physical change (or not); and/orone or more chemical reactions (or not) and physical changes (or not),either alone or in combination. For tattoo removal, one example of anegative therapeutic effect is bubble formation in the dermis. Thereare, of course, other negative therapeutic effects that one of ordinaryskill in the art, having the benefit of this disclosure, will recognizefor the one or more types of light output of particular interest (fortattoo removal, skin treatments, and/or for other applications). Aresult-effective event against a negative therapeutic effect may counterone or more negative therapeutic effects or events, alone or incombination. The result-effective event may include one or moreoccurrences that, alone or in combination, may counter such negativetherapeutic effect or event in one or more ways, either alone or incombination, e.g., prevention, resolution, reduction, inhibition,neutralization, avoidance, amelioration, blockage, forestalling,interruption, obstruction, prohibition, stoppage, acting, accelerating,breaking down, solving, advancing, expediting, stimulating, removing,pacing, controlling, causing, generating, speeding, warming, cooling,facilitating, urging, checking, slowing, etc. There are, of course,additional such ways beyond those listed which will be apparent to oneof ordinary skill in the art having the benefit of this disclosure.

In one embodiment, a chemical facilitator sufficient to provide aresult-effective event against a negative therapeutic effect isprovided, or a facilitating step is performed, as one one or moredistinct events at t₁, t₂, t₃, . . . , t_(n), where each event at t₁,t₂, t₃, . . . , t_(n), etc. is defined using a therapeutic referencescale. A therapeutic reference scale may be anything of interest to aphysician, clinician, or other caregiver related to the patient andtherapy involved. Exemplary therapeutic reference scales include,without limitation: time, presence or absence of a condition, occurrenceof an event, etc. Note, too, that each event at t₁, t₂, t₃, . . . ,t_(n) may be defined using the same or different therapeutic referencescales; related or unrelated therapeutic reference scales; etc.

During a tattoo procedure, heating may be localized, and/or may produceor otherwise cause or promote localized bubble generation. Typically,tissue, skin, tattoo pigment, the dermis portion, etc. are heated duringtreatment. Resolution of the whitening reaction may be caused at leastin part by the cooling of one or more heated portions. Thus, in oneexemplary aspect, an exemplary embodiment of the invention may include acooling step or process before, during, or after light exposure,chemical application, etc., to provide cooling related to the treatment(e.g., cooling of the skin, the dermis, the treatment area, a chemical,an applicator for light, an applicator for a chemical, an emitter outputdelivery system, a bandage, a patch, a skin contact device, etc.).

Again, whitening resolution typically occurs over time following laserexposure. It has been shown that whitening reaction resolution overabout twenty minutes or more following laser exposure may proveadvantageous, particularly where such 20-minute period is immediatelyfollowed by one or more laser exposures (with a similar 20-minuteresolution period following each such laser exposure). Such processincluding 20-minute intervals between laser passes may be referred to bysome as the “R20” method. The R20 method has significant drawbacks,however. For example, use of the R20 technique (e.g., including fourlaser passes) may require up to eighty minutes (or more) of treatmenttime per treatment session, which is impractical. Thus, there has been asubstantial and long felt need for a treatment system and method fortattoos that is effective in shorter sessions.

An exemplary laser pass and the R20 method is generally illustrated inFIGS. 5A, 5B, and 5C. As shown in FIG. 5A, light 200 from an emitter 210penetrates the skin portion 30 and impacts the tattoo 10 within thedermis 70. As a result, bubbles 220 form. In addition, tattoo pigmentdye 230 is released proximate the tattoo, e.g., from the destruction ofphagocytosed or rephagocytosed cells of tattoo 10.

FIG. 5B illustrates the skin portion 30 following completion of thelaser pass illustrated in FIG. 5A. As shown, there is an increase in theamount of dye 230 proximate the tattoo 10, as well as an increase in thenumber of bubbles 220.

If a subsequent laser pass would be performed upon the skin portion 30as shown in FIG. 5B, such subsequent pass would be ineffective. Asnoted, for example, by Kossida et al., the administration of two passesseparated by 30 seconds to 20 minutes has been tested and is not moreeffective than a single pass.

Accordingly, in the R20 method, to accomplish multiple laser passes, adelay of about 20 minutes or more is required for a skin portion tonaturally resolve from an initial state as illustrated in FIG. 5B to atherapeutically more light-receptive state as illustrated in FIG. 5C(i.e., for example, a state including fewer bubbles 220, more disperseddye 230, etc.). Put another way, while a skin portion 30 can go fromFIG. 5A to FIG. 5B relatively quickly, for that same skin portion to gofrom FIG. 5B to FIG. 5C takes much longer, i.e., about 20 minutes ormore.

The R20 process also is generally illustrated in the flowchart of FIG.4. As shown, a single laser therapy session lasts from start 100 to end140. In step 110, light therapy first is performed on a treatment area.Then, at step 120, the physician must wait for about 20 minutes or morefor whitening reduction to occur naturally. After the delay, thetreatment area assumes a therapeutically more light-receptive state, andthe physician may choose at step 130 to end treatment (i.e., a one-passlaser session) or continue light therapy with another laser pass (i.e.,a multiple-pass laser session). As shown in FIG. 4, in a multiple-passlaser session step 110, step 120, and step 130 are repeated until thesession ends at step 140.

As described in this disclosure, very rapid resolution of one or morewhitening reactions and/or one or more whitening reaction results may beachieved in one or more treatment processes or steps including the useof a chemical. See, e.g., FIG. 6 and FIG. 7. Such treatment includingchemical use eliminates, among other things, the problematic “WAIT” stepof prior methods for tattoo lightening or removal (e.g., the R20method). In that way, without limitation, such chemical and its use maybe regarded as a treatment facilitator and facilitating step,respectively. Compare, e.g., FIG. 6 and FIG. 7 with FIG. 4 (stopsign/wait step in FIG. 4 only).

As illustrated in FIG. 6, in one embodiment a light therapy sessionstarts at step 2000 and ends at step 2050. First, a determination ismade at step 2010 whether to use a chemical facilitator prior to lighttherapy. If no chemical facilitator is used, the method proceeds at step2030 with a treatment area receiving light therapy. However, where achemical facilitator is used, the method provides for step 2020, whereina chemical facilitator is provided to the treatment area before theperformance of light therapy step 2030. Following light therapy, thedetermination is made at step 2040 whether to provide additional lighttherapy treatment. If so, step 2010, step 2020, and step 2030, as wellas step 2040, are repeated one or more times. The therapy session endsat step 2050 when it is determined at step 2040 that no further lighttherapy is to be provided during the session.

In accordance with the disclosure, variations on the embodimentillustrated in FIG. 6 may be used depending upon the circumstancesinvolved in a particular application. For instance, one alternateembodiment is illustrated in FIG. 7.

As shown in FIG. 7, a laser therapy session extends from its start 3000to its end 3090. An initial decision is made at step 3010 regarding useof a chemical facilitator (or not). The facilitator might be used, forexample, to achieve a desired inhibition of whitening during asubsequent light therapy step. If no chemical facilitator is desired,light therapy is performed on a treatment area at step 3020. At thatpoint, following light exposure, the determination is made at step 3030whether additional light therapy is warranted for the treatment area. Ifso, a return to step 3010 follows.

If at step 3010 the determination is made to use a chemical facilitator,then a subsequent determination is made at step 3040 whether chemicalfacilitator use will occur concurrent with the application of light tothe treatment area. If no concurrent use is planned, then chemicalfacilitator is provided to the treatment area at step 3050, and themethod of the embodiment proceeds to step 3020. Where concurrentdelivery of light and a chemical facilitator is not desired, applicationand delivery of chemical facilitator may occur at step 3050 prior tolight exposure using an appropriate embodiment of the described systemfor the particular circumstances involved. One example of such anembodiment and its use for pre-treatment with chemical facilitator(e.g., before a laser use) is illustrated in FIGS. 10A and 10B.

At step 3040, however, if the determination is made to concurrently usea chemical facilitator and light therapy, then the method proceeds tostep 3060 where the chemical facilitator is provided to a treatment areaalong with light. One exemplary embodiment of the disclosure thatprovides for concurrent delivery of chemical facilitator and light isillustrated in FIGS. 9A and 9B. Note, too, that depending upon thespecific circumstances involved, such exemplary embodiment also iscapable of providing a pre-treatment with a chemical facilitator priorto light exposure.

Following step 3020, and following step 3060, the exemplary methodproceeds to step 3030, where a determination is made whether to provideadditional light therapy to the treatment area. If no additional lighttherapy is required, the method proceeds to step 3070. At step 3070, adetermination is made whether application or delivery of additionalchemical facilitator to the treatment area is needed. Such additionalchemical facilitator might be required, for example, to rapidly clearany remaining whitening effects before the end of the session at step3090. Of course, the determination made will depend upon thecircumstances involved in the specific treatment. If additional chemicalfacilitator is required, it is provided at facilitating step 3080 andthe session then ends at step 3090; otherwise, the method proceeds fromstep 3070 to the end at step 3090.

In one embodiment, a chemical facilitator includes a fluorocarbon. Inanother embodiment, the chemical used includes a derivative of decalin.In another embodiment, the chemical used is an organic compoundincluding fluorine in which 0-100% of hydrogen is replaced, e.g., bydeuterium. In another embodiment, the chemical includeshydrofluorocarbons. In another embodiment, the chemical includes1H-perfluoropentadecane (hentriacontafluoropentadecane). The chemicalmay include one or more of: (i) a fluorocarbon, (ii) a surfactant, (iii)a fluorosurfactant, and (iv) a non-hydrocarbon surfactant.

In one exemplary embodiment, very rapid resolution of whitening reactionresults includes the use of a chemical including perfluorodecalin(C₁₀F₁₈). Perfluorodecalin is a fluorocarbon, and a derivative ofdecalin, in which all of the hydrogen atoms are replaced by fluorineatoms. Perfluorodecalin in general is regarded as chemically andbiologically inert, and stable up to about 400° C. As more specificallydescribed by Tsai, “[l]ike liquid perfluoro-n-alkanes (CnF2n+2, n=5-9)(Tsai, 2009), perfluorodecalin (C10F18) is a colorless, odorless,non-toxic, non-flammable, thermally stable, non-ozone-depleting, andheavy compound (high density and viscosity) with high volatility, lowsurface tension, high gas solubility, and very low solubility in water.Currently, it is primarily and increasingly used as a blood substitute(Lowe, 2008). In addition, it can be used as a contrast agent in avariety of diagnostic imaging techniques (e.g., ultrasound image) (Hallet al., 2000), temporary intraoperative vitreous substitutes invitreoretinal surgery (ophthalmology) (Heimann et al., 2008), cosmeticand ointment additive for repairing burned skin and wound surface(Oxynoid et al., 1994), liquid ventilation used in the drug delivery(Kraft, 2001), carrier of glassified microspheres that contain vaccines(Coghlan, 2004), reaction medium in organic and organometallic syntheses(Hibbert et al., 1997; Sandford, 2003), volatile surfactant used for gasmodification of lubricants and in optics and liquid lasers (Stoilov,1998), and tracer gas in the environmental quality modeling in theocean, and groundwater (Watson et al., 1987; Deeds et al., 1999).”

FIG. 8 illustrates an exemplary embodiment including perfluorodecalindelivery to a treatment area using a patch 400 including perfluordecalin300. The patch 400 includes a first portion 410 and a second portion 420including perfluorodecalin 300. As shown in FIG. 8, the patch ispositioned on a skin surface 40, and perfluorodecalin has transferredfrom the patch 400 to an area and volume proximate the tattoo 10. Asillustrated, perfluorodecalin may be present at various times not onlyproximate the tattoo 10, but also proximate the epidermis 60, thestratum corneum 50, and the environment 430 proximate the skin surface.

As illustrated in FIG. 8, as the patch 400 is moved across the skinportion 30 in an initial state following a laser pass (e.g., a state asshown for example in FIG. 5B), a very rapid, and perhaps almostinstantaneous, reduction of whitening occurs, as evidenced by areduction of the bubbles 220 associated with the transfer ofperfluorodecalin from the patch 400 to an area proximate the tattoo andwhitening.

In one embodiment, a patch or other chemical facilitator delivery meansmay be physically and/or physiologically similar to skin. Such means maybe adapted for intimate contact with a patient; may be substantiallyoptically transparent; and/or may be soothing, benign, comfortable,and/or pleasant in use. Further, the patch or other chemical facilitatordelivery means may be cooperative, e.g., with skin or other aspects of aparticular therapy, to help promote one or more result-effective eventsagainst one or more negative therapeutic effects.

The perfluorodecalin need not be applied to the treatment area using apatch, as illustrated for example in FIG. 8. Other chemical andfacilitator delivery means also may be used, depending on thecircumstances involved in a particular application. For instance,application of perfluorodecalin to a treatment area from a vial or otherliquid container using a cotton swab has been shown to effectivelyresolve whitening in laser therapy within seconds. See the Pilot Studyresults included in this disclosure.

FIG. 9A illustrates an exemplary embodiment including prevention of anundesired whitening effect by using a patch including perfluorodecalin.As shown in FIG. 9B, a tattoo portion 10 is exposed to a light output520 delivered through the patch 500. Prior to light exposure, the patch500 is placed on a skin surface 40 proximate tattoo 10. The patch 500includes a surface or region 510 that may be substantially impermeableto the perfluorodecalin 300. The region 510 may be within the interiorof a patch, and/or the region 510 may form a portion or more of an outersurface of the patch. Perfluorodecalin in the patch 500 between thesurface 510 and the skin surface 40 transfers into the skin portion 30including tattoo 10. The patch may be optically transparent. The patchincluding perfluorodecalin also may be optically transparent.

In one embodiment, the patch 500 remains in place on the skin surfaceuntil a sufficient amount of perfluorodecalin 300 enters the skinportion 30 proximate the tattoo 10 to achieve a desired therapeuticresult. A light output 520 from an emitter 530 is delivered through thepatch 500 to treat the tattoo 10. See FIG. 9B. The emitter 530 may bemoved as necessary across the patch to treat a desired skin area. Theemitter 530 may be in contact with the surface 510, or may be spaced adistance from it. In an alternate embodiment, the patch 500 may beremoved prior to laser therapy, so that light may directly impinge uponthe skin portion 30 including perfluorodecalin 300 without passingthrough the patch 500.

As illustrated in FIG. 9B, perfluorodecalin proximate the tattoo portiontreated effectively inhibits whitening due to the laser pass. Theformation of bubbles 220 may be prevented in part, and/or rapid or nearinstant clearing of a substantial portion of formed bubbles may occur.

FIG. 10A and FIG. 10B illustrate another exemplary embodiment of thedisclosure, including perfluorodecalin delivery to a treatment areausing a swab including perfluorodecalin. The tip 610 of the swab 600 mayinclude cotton or other suitable material to promote application ordelivery of the perfluorodecalin 300. Perfluordecalin 300 may beprovided to the swab tip 610 by immersing or otherwise contacting thetip 610 at least in part in a quantity of a perfluorodecalin-includingsubstance (e.g., without limitation, a gel; liquid perfluorodecalin in avial or other container or carrier; etc.). In one embodiment, the swab600 itself may include perfluordecalin 300, e.g., in the tip itself, orin a chamber within the body of the swab 600. The chamber may be in, orbe capable of being placed in, direct fluid communication with swab tip610 or other delivery point. Of course, other configurations may be usedtoo, as will be apparent to one of ordinary skill in the art having thebenefit of this disclosure.

As shown in FIG. 10A, perfluorodecalin may be transferred to an area orvolume proximate the tattoo 10 by moving the tip 610 includingperfluorodecalin one or more times across a portion of the treatmentarea. Following such transfer, the swab or other perfluorodecalindelivery means may be removed, and a light output 620 from emitter 630may be used to treat tattoo 10. Similar to the approach illustrated inFIG. 9A and FIG. 9B, delivery of the perfluorodecalin 300 proximate thetattoo 10 helps prevent undesired whitening following a laser pass. Itis believed that whitening prevention may result from one or morefactors, alone or in combination, including without limitation: theprevention of bubble formation, the rapid resolution of bubbles formed,and one or more other circumstances.

In one embodiment, perfluorodecalin is effective as a facilitatoragainst whitening in a laser tattoo lightening or removal procedure.Regardless of the specific embodiment employed for facilitator delivery,use of a chemical facilitator against whitening may permit a physicianto treat tattoos more rapidly than prior methods, e.g., substantiallyless than about twenty minutes or more between laser passes. Or, fromanother perspective, using prior tattoo treatment systems and methods,typically it takes about twenty minutes or more for a treatment site totransition from initial states (such as those as illustrated for examplein FIG. 5A and FIG. 5B) to subsequent light-therapy-ready states (suchas those as illustrated for example in FIG. 5C). Chemical facilitatoruse speeds such a transition.

Under the prior R20 and other treatment techniques, whitening due to asingle laser pass diminishes over about 20 minutes or more. Treatmentareas transition slowly from an initial state, and ultimately such areasnaturally assume an improved state that generally is more receptive tolaser treatment as compared to the initial state. Accordingly, theamount of total treatment time associated with prior R20 and othertreatment techniques is quite significant.

In large measure, prior approaches are problematic due to theconsiderable waiting times required in every treatment session.Consider, for example, a physician having to wait twenty minutesfollowing each single laser pass to continue a multiple pass lasertreatment session. Such delay is inconvenient from a time-managementperspective for both the physician and the patient. Further, the delaymakes the management and flow of patients through the physician's officequite difficult, especially where a large number of patients may betreated each day, and also where waiting room and clinical space forperforming therapeutic procedures is limited. Although the priormultiple pass method may provide greater efficacy as compared to asingle pass method, the required lengthy treatment time may limitadoption of the prior multiple pass technique.

The invention and this disclosure effectively address this and otherproblems of prior methods. One exemplary embodiment relates to use of afacilitating step to cause a treatment area to assume more rapidly thesame or a similarly receptive state for laser treatment. In some cases,the receptive state may be an improved or more receptive state from anoptical and/or therapeutic perspective. The facilitator used may includea chemical, and the facilitating method portion may involve or includeone or more steps including chemical use. The facilitator may be achemical including perfluorodecalin. The chemical also may be a chemicalnot including perfluorodecalin. For clarity and convenience only, andwithout limitation, the Figures of this disclosure illustrate use ofperfluorodecalin as a chemical facilitator. The invention and thisdisclosure, however, are not necessarily so limited. However, chemicalfacilitator use, and the performance of a facilitating step includingchemical use, may enable treatment sites to transition much more rapidlyfrom initial states (examples such initial states shown in FIGS. 8,9A-B, and 10A-B) to later states (an example of such later states shown,e.g., in FIG. 11).

Although the specific treatment mechanism of action may involve multiplefactors, it is believed that tattoo pigment heating may perform a role,due to the tattoo pigment including one or more metals and/or metalparticles. Tattoo pigment heating may result in a scattering orintercellular dispersion of tattoo pigment to promote clearing. Cellsincluding pigment (e.g., phagocytosed and/or rephagocytosed tattoopigment particles) may be heated or otherwise treated to induce cellbreakdown, destruction, or dispersion, that permits a clearing out ofthe tattoo pigment dye via the lymphatic system. See, e.g., FIG. 11,which illustrates dye 700 proximate tattoo 10 during laser treatment.Application of laser light rapidly increases local enthalpy, andaccompanying this rapid heating and/or the other factors, almostinstantaneous bubble formation may occur. Bubble formation, which oftenmay be identified by a color change in the treatment area (e.g., awhitening) is generally regarded as undesirable, at least in partbecause bubble presence is thought to tend to inhibit opticalpenetration at the treatment site, and may result in a required intervalof about twenty minutes or more between laser exposures and/or laserpasses to allow the bubbles to resolve.

Direct or indirect delivery of a chemical to a treatment site via acarrier or other applicator assembly may promote resolution of whiteningand/or other undesired conditions inhibiting treatment through one ormore of: (i) reduction of local surface tension; (ii) gas absorption;(iii) penetration into tissue or skin; (iv) enhancement of gaseousdiffusion (transcellular and/or otherwise); (v) migration or flowthrough tissue; (vi) refractive index matching; (vii) filling voids orgas-filled interstices; (viii) reduction of optical scattering; and (ix)optical clearing. These factors, and perhaps others, may relate to theobserved very rapid resolution with the use of a chemical facilitator,such as one including perfluorodecalin. Perfluorodecalin, for instance,generally has excellent gas-carrying and gas-absorbtion properties, asdemonstrated for example by its use in liquid breathing applications.Using perfluorodecalin, post-laser whitening resolution times of lessthan about thirty seconds, and more particularly of less than about fiveseconds, may be achieved. The actual time will depend of course on thespecific circumstances involved in a particular application (e.g., sizeof the treatment area). Likewise, laser sessions for tattoo removal maytake only a few minutes of total treatment time.

Resolution of conditions tending to inhibit treatment may be identifiedin various ways. In addition to accepted techniques for measurement ofpertinent parameters (e.g., bubble size, density, count, dissolution), acolor change generally characterized by a darkening of all or a portionof a whitened area may be observed. In some cases, a treatment area mayresolve and turn from white to gray or black, or to the original colorof the tattoo or portion treated. Rates of changes in color change, oneor more parameters, etc., also may be identified.

In some laser treatments that include use of a R20 technique, theobserved whitening (see, e.g., FIG. 5B as an exemplary illustration ofsuch whitening) mostly goes away in 20 minutes, but there can be one ormore areas (e.g., relatively small subsets of the treatment area) thatresist and that do not resolve very well in that timeframe. However, ifone were to wait much longer, i.e., for up to a month more (as in atypical treatment method that involves multiple treatment sessions overa period of months), such areas eventually would resolve substantiallyand most or all whitening would go away.

In one exemplary embodiment of this disclosure, the delivery ofperfluorodecalin following one or more laser passes substantiallyeliminates such areas that otherwise (i.e., without perfluorodecalinuse) would resist and not resolve very well in about twenty minutes.Accordingly, a tattoo treatment or procedure using perfluorodecalin asdescribed herein may be more efficacious than R20 and other treatmenttechniques by providing rapid resolution of a substantially complete orentire treatment area (e.g., up to nearly 100% resolution, completeresolution), e.g., in a few minutes, in less than five minutes, almostinstantaneously, more rapidly than R20, in a few seconds, in less thanfive seconds, etc., again depending upon the specific circumstancesinvolved in a particular application.

FIG. 12A illustrates a tattoo portion 12 during a multiple laser passtherapy session. More specifically, FIG. 12A illustrates the tattooportion 12 in a state that may follow one of the later laser passes in amultiple pass therapy. As shown, significant amounts of dye 800, e.g.,from phagocytosed cells including dye pigment, surrounds the tattoo 12,which is shown as being smaller in size than the tattoo 10 in theearlier Figures to reflect multiple laser passes. Considerable whiteningis present, as evidenced by the large number of bubbles 810 at thetreatment site. The absence of perfluorodecalin or any other facilitatorin FIG. 12A might suggest, for example, that the last laser passperformed was completed without prior or concurrent use of a chemicalfacilitator. Had such a facilitator been used, a state more closelyresembling the one shown in FIG. 12B would be expected (depending, ofcourse, on the specific circumstances involved). In FIG. 12B, reducedwhitening as compared to FIG. 12A is shown, as evidenced by relativelyfewer bubbles 910, and some remaining facilitator 900 is present. Asfurther shown, the amounts of dye 920 and the size of the treated tattooportions 12 are somewhat similar in FIG. 12A and FIG. 12B, although thatneed not necessarily be the case. Indeed, use of a chemical facilitatormay result in more effective therapy overall.

FIG. 13A illustrates one exemplary embodiment in which a swab 1000including perfluorodecalin 1010 is used in a tattoo procedure includingmultiple laser passes and whitening. Perfluorodecalin 1010 from the swabtip 1020 is provided in sufficient quantity to a treatment areaincluding bubbles 1030 and tattoo pigment dye 1040, so that whitening issubstantially resolved. See FIG. 13B.

Perfluorodecalin use has an optical clearing effect. This effect mayitself improve the efficacy of the system and method of the invention ascompared to prior art techniques, e.g., those including a typicalapproach of “wait a month or more” or “wait 3-6 weeks” between lasertreatment sessions, R20 methods, etc. Indeed, perfluorodecalin mayfacilitate laser treatment of any (or at least a wide variety of)generally undesirable conditions in the dermis (or elsewhere) for whichlaser treatment is used to promote the elimination or removal of suchconditions in whole or in part. In one aspect, an exemplary embodimentof the invention includes eliminating at least in part an undesirableskin condition for which treatment with an emitter output promotes atherapeutic benefit, including: (a) delivering perfluorodecalin to anarea of skin proximate the undesirable skin condition; and (b) exposingthe area of skin to a therapeutic amount of an emitter output. Achemical facilitator other than one including perfluorodecalin may beselected for use based on its desirable characteristics (e.g., excellentskin penetrating ability, desired therapeutic results, and/or otherfactors). In some cases, the time between laser sessions may besubstantially shortened to less than about 3-6 weeks with chemicalfacilitator use.

In accordance with one aspect of the disclosure, tattoo treatment may beachieved by pre-converting at least a portion of the blood proximate thetattoo to metHb prior to laser treatment. The “pre-conversion” to metHbprior to laser treatment may be achieved with the topical application ofbenzocaine and/or similar drugs. (For simplicity, only benzocaine shallbe referred to herein, but the invention is not necessarily so limited.)The benzocaine penetrates the skin and chemically converts oxyhemoglobin(HbO₂) and deoxyhemoglobin (RHb) into methemoglobin (met-Hb) withefficiency and speed.

The pre-conversion of one or more hemoglobin species into metHb maybring the optical absorbance of the vessels in the treatment area intoan effectively unchanging conformance, thus reducing or eliminating thepossibility of sudden and unpredictable changes during laser treatment,and making adverse events and/or poor treatment outcomes less likely.

At some wavelengths, such as in the visible portion of the spectrum,metHb has a lower absorption than some other hemoglobin species. Atother wavelengths, such as in the NIR (750 to roughly 1500 nm) metHb hasa higher absorbance than most other hemoglobin derivatives. The unknownrelative concentration of these hemoglobin species can grossly alter theresponse proximate the tattoo to a given optical treatment condition.

Benzocaine may be delivered in many ways, e.g., as a spray, apre-treated wipe, a pre-filled applicator, a swab, a patch, or a topicalcream. In one embodiment, a benzocaine delivery means like these orothers supplies a controlled concentration of the drug to the treatmentsite (e.g., the patient's skin), so as to avoid the problems andpotential adverse events associated with the application of uncontrolledconcentrations. For example, benzocaine sprays and similar may inducemethemoglobinemia under certain circumstances, a treatable (methyleneblue injection or administration of oxygen) but cyanotic (asphyxiating)condition that is potentially life threatening, especially in newbornswho have low circulating volumes of blood.

In accordance with one aspect of the present disclosure, a transparentflexible dressing or patch, comprising a lipid rich gel, may serve as abenzocaine delivery means. The gel includes a desired concentration ofbenzocaine. The concentration of benzocaine in the gel acts as a limitor check on the conversion to metHb, in that the amount of benzocainedelivered from use of the dressing or patch will not exceed the amountof benzocaine that is preloaded into the gel.

In accordance with one aspect of the disclosure, the benzocaine deliverymeans may comprise a flexible dressing or patch including a gel that istransparent to the output of the treatment laser. During treatment, aphysician may leave the gel in place and fire the laser through it.Alternately, a physician may remove the gel prior to treatment laseruse, and work on bare skin. Also, the physician may reapply the gel fromtime to time, as appropriate.

Similarly, perfluorodecalin may be delivered in many ways, e.g., as aspray, as a pre-treated wipe, as a prefilled applicator, in a patch, ina gel, with a swab, as topical cream. In one embodiment, a benzocainedelivery means, like such examples listed above or others, supplies acontrolled concentration of perfluorodecalin to the treatment site(e.g., the patient's skin), so as to avoid any problems and potentialadverse events associated with the application of uncontrolledconcentrations.

In one aspect, in one embodiment of the disclosure including a lipidrich gel, the gel may include any non-polar, non-aqueous material. Forexample, gels including fats, fatty acids, mono- and poly-glycerides,glycol lipids, polyketides, glycerophospholipids, and sphingolipids maybe used. In addition, lipid rich gel may be substances includingnon-polar, non-aqueous organics. Examples of such substances include, byway of example and without limitation, hexane, septane, nonane, naphtha,naphthalene, polyaromatic molecules, perfluorohydrocarbons,perfluorodecalin, freons, octane, n-hexane, and similar molecules.

In accordance with one aspect of the present disclosure, a transparentflexible dressing or patch, comprising a lipid rich gel, may serve as aperfluorodecalin delivery means. The gel includes a desiredconcentration of perfluorodecalin. The concentration of perfluorodecalinin the gel may act as a limit or check on the presence and/or amount ofgas at the treatment site, and/or provide or promote enhanced opticalclearing. A gel that is fully organic, mixed aqueous/organic and/orfully aqueous may serve as a carrier. Also, a gel may include anemulsion that includes one or more chemicals or substances of interest(i.e. perfluorodecalin).

In accordance with one aspect of the disclosure, the perfluorodecalindelivery means may comprise a flexible dressing or patch including a gelthat is transparent to the output of the treatment laser. Duringtreatment, a physician may leave the gel and/or dressing or patch inplace and fire the laser through it. Alternately, a physician may removethe gel and/or dressing or patch prior to treatment laser use, and workon bare skin. Leaving the flexible dressing or patch in place may helpreduce or confine the ejection or discharge of debris from the treatmentsite; defend against ejecta; ameliorate and/or eliminate unwantedconditions, etc., so as to help the clinician and/or patient, e.g., byacting as a shield; by collecting discharge; by absorption; by selectivewithdrawal or placement of substances; by cleaning, clearing, and/orcontaining a treatment area; by deflection, reflection, or the like; bybeneficial scattering or redirection; by containment; by encapsulation;by disinfection; by removal; by transformation; and/or by deliveringanesthetics, Gallenic topicals/drugs, or other patient comfort enhancingmaterials; etc. The patch may be used alone or in conjunction with adevice to selectively perform, help perform, promote, and/or assist inthe efficacy of one or more of the described desirable functions,processes, materials, etc.

In one exemplary embodiment, a carrier or applicator is provided. Thecarrier or applicator is adapted to be positioned proximate a skintreatment site. The carrier or applicator may include a flexible,transparent portion. A chemical including perfluorodecalin, anothergas-absorbing chemical, or other chemical facilitator may be disposedbetween the flexible, transparent portion and the skin treatment sitewhen the carrier or applicator is positioned proximate to the skintreatment site. In one embodiment, the flexible transparent portion maybe disposed on a first side of the carrier or applicator, the first sidebeing generally opposite from that portion of the carrier or applicatorthat may be in full or partial contact with the skin.

The flexible, transparent portion of the carrier or applicator may besubstantially impermeable to perfluorodecalin (or other gas-absorbing orchemical facilitators) in its liquid state, in its gaseous state, or inboth its liquid and gaseous states. Such portion of the carrier orapplicator may tend to prevent the loss of perfluorodecalin or otherchemical facilitators, e.g., due to evaporation. Moreover, as theflexible, transparent portion of the carrier and/or the perfluorodecalinand/or other chemical facilitator warms (e.g., with body temperature),the vapor pressure of the perfluorodecalin and/or other chemicalfacilitator will increase. Under such circumstances, the flexible,transparent portion of the carrier or applicator may further driveperfluorodecalin and/or other chemical facilitator into the skintreatment site, as both liquid and gas and all permutations of liquidonly, gas only, and liquid plus gas.

In one embodiment, a system for the delivery of perfluorodecalin orother chemical facilitator to a skin treatment site may include means topromote driving perfluorodecalin or other chemical facilitator into theskin treatment site. Such means may include or provide, either alone orin combination, one or more of the following: vibration, ultrasound,heat, pressure, cooling, chemical gradient, and chemical actionpotential.

In another embodiment, a system for the delivery of perfluorodecalin orother chemical facilitator to a skin treatment site may include a patchor other device that is transparent to a laser output; that includes atop surface including a layer that is impervious to fluids; that isflexible and conformable to a portion of a patient's body; that includesa gel capable of hosting perfluorodecalin; and that includes a means topromote the temporary residence of perfluorodecalin in the gel. In oneembodiment, the system may be rigid in part. In one embodiment, thesystem may include a release liner, foil pack, pouch, etc. to in wholeor in part house the patch or other device prior to use with a patient,and to help promote the temporary residence of perfluorodecalin in thegel.

In another embodiment, a system and method for tattoo treatment includesdelivery of perfluorodecalin or other chemical facilitator to a skintreatment site following pretreatment or preparation of the site.Pretreatment or preparation may include, alone or in combination, useproximate the skin treatment site of one or more of the following: afractional laser; an ablative fractional laser; a non-ablativefractional laser; one or more micro-needle arrays; a heating apparatus,e.g., a heating pad or surface; a cooling apparatus for cooling a skinportion; a chemical, e.g., glycolic acid or dimethyl sulfoxide (DMSO).Pretreatment or preparation may tend to increase the permeability of askin treatment site prior to the delivery of perfluordecalin to thesite. Other pretreatments or preparations also may be used to createconditions to promote therapeutic benefit, e.g., cleaning the treatmentarea. A chemical facilitator, e.g., perfluorodecalin, also may be usedin a pretreatment or preparation.

In another embodiment, a system and method for tattoo treatment includesdelivery of perfluorodecalin or similar other chemical using a transportdevice for the chemical. The transport device generally promotespenetration of the perfluorodecalin or other chemical into the treatmentarea. Examples of transport devices include, without limitation: one ormore needles, one or more syringes, a microneedle array, one or moreinjectors, glycolic acid, DMSO, penetrating oils, freons, iontophoretictransdermal systems, etc. that enhance transdermal transfer and/orpermeability.

The optical power densities used to treat tattoos can be uncomfortable;pain may induce patient motion and distress, thus reducing calm, evenproper optical delivery of the therapeutic laser beam by the operatingphysician. Thus, in accordance with one aspect of the disclosure, theadministration of a drug for pre-conversion of one or more hemoglobinspecies into metHb, and/or the delivery of a chemical facilitator (e.g.,perfluorodecalin), occurs along with the administration of ananaesthetic. In some cases, the pre-conversion drug may also serve as ananaesthetic, either alone or in conjunction with one or more otheranaesthetic agents. Benzocaine, for example, is an effectivepre-conversion drug that also is an effective topical anaesthetic(indeed, this is its formal indication for use). An anaesthetic agent,which may or may not promote pre-conversion, may be administered topatients in addition to perfluorodecalin (e.g., before, during, of afteradministration of perfluorodecalin).

Other dermatological conditions may benefit from treatment in accordancewith one or more aspects of the disclosure, for example by changing(increasing or decreasing) the optical absorption of the treatment site(rendering it more susceptible to certain wavelengths of treatmentlight), reducing pain, or both. Such conditions and treatment sitesinclude, without limitation, angiomas, hemangiomas, telangiectasias,varicosities, fine lines, wrinkles, scars, skin surface imperfections,areas of skin dispigmentation, freckles, age spots, solar lentigines,acne, hyperpigmentation, hypopigmentation, benign pigmented lesions, andother such or related conditions. Further, both the Title and theAbstract of this application are provided for convenience only, andshould not necessarily limit the scope of the invention and disclosure.

In accordance with another aspect of the disclosure, in some embodimentsit may be desirable to alter the preferential (selective) absorbance ofone side of the vasculature in the sense of arterial vs. venous bloodusing the pre-conversion method described herein.

In accordance with another aspect of the disclosure, in some embodimentsit may be desirable to treat background dyschromia (red or brown) bychanging the absorbance of blood using the pre-conversion methoddescribed herein and also allowing use of more deeply penetratingwavelengths.

In accordance with one aspect of the disclosure, topicals and otheragents that may promote the formation of metHb may be used. Many othertopically applied substances can increase the local concentration ofmethemoglobin in the vasculature. Antibiotics, such as trimethoprim,sulfonamides and dapsone; local anesthetics, such as articaine,lidocaine and prilocalne; and other substances such as aniline dyes,metoclopramide, chlorates, bromates and nitrates, especially bismuthnitrate, can convert oxyhemoglobin and deoxyhemoglobin intomethemoglobin.

Exemplary Treatment Systems and Methods:

The following are only a few exemplary embodiments of treatment systemsand methods in accordance with the disclosure:

For Port Wine Stains:

Apply a small (roughly 2 cm²) pad saturated with benzocaine, or up to20% or more benzocaine, formulated so as to be lipophilic. Cover with anocclusive dressing for a few minutes. Discard dressing and clean offresidue with an acetone wipe. Apply several coats of perfluorodecalinwith a cotton-tipped applicator, working the perfluorodecalin insomewhat. Cover the benzocaine/perfluorodecalin-treated area with atransparent dressing or patch (cut to size). Fire the treatment laserthrough the transparent dressing or patch.

Laser selection: Q-switched alexandrite (755 nm) or Q-switched Nd:YAG(1064 nm). The objective is to get greater penetration depth in the NIRto treat the full thickness of the lesion. At optimal fluence, one passin the NIR may be sufficient. Visible dye lasers also work, but becausethey are too strongly absorbed, they may treat too superficially.

Fluence: Start with a relatively low fluence. Increase as necessary toachieve a desired treatment. metHb has a higher absorbance in the NIRthan HbO₂ or rHb. All three hemoglobin species have greater penetrationdepth in the NIR than in the visible.

For Tattoos:

The perfluorodecalin will have its best effect if it is degassed andappropriately delivered in a lipophilic gel dressing. In other words, itwill assist in removing bubbles from areas of the tattoo that have beentreated with a laser pulse, allowing greater penetration of subsequenttreatment pulses without having to wait as long for the bubbles to beabsorbed as would be the case with skin that has not been treated withperfluorodecalin. Perfluorodecalin can absorb considerable amounts ofvarious gasses. Exposing degassed perfluorodecalin to atmosphericpressures for long periods of time will render it less effective. Atransparent treatment patch composed of a suitable material such as alipophilic gel preloaded with degassed perfluorodecalin or similarstored in a gas tight package until ready for application to the skinwould assist in the speed of removal of tattoos by absorbing gas bubbles(or rendering them less troublesome) produced by the treatment laserlight, said bubbles rendering the tissue less transparent to subsequenttreatment laser light.

A chemical facilitator may be degassed in a variety of ways. One way isto expose it to reduced pressure or vacuum, allowing any dissolvedgasses in the liquid to boil off and resulting in a lower vapor pressureof those gasses than in the tissue to be treated. A typical means wouldbe to freeze the chemical facilitator into a solid, expose the solid tohard vacuum, and then slowly allow the solid to melt into a liquid so asto allow removal of dissolved gasses without excessive evaporation. Thisis the “freeze-pump-thaw” method.

Exposing the gel or system to partial pressures lower than thosetypically encountered within the tissue immediately following laserirradiation until the chemical facilitator alone, or in the gel or inthe system fell below that within the tissue would result in a conditionwhere gas would dissolve into the chemical facilitator from the tissueuntil an equilibrium condition was achieved. The lower the partialpressure of gas within the gel or system, the more gas that can betransferred from the tissue.

In one exemplary embodiment, then, a method for resolving whiteningfollowing laser therapy includes applying perfluorodecalin to atreatment area prior to exposure of the treatment area to a laseroutput, wherein the perfluorodecalin is in a partially degassed statewhen applied to the portion of the whitening.

For Neonates:

One of ordinary skill in the art, having the benefit of the presentdisclosure, will recognize the particular benefits of the disclosure forthe treatment of neonates. Topical anesthetics in accordance with thedisclosure, e.g., benzocaine (or similar), convert fetal hemoglobin tomet fetal hemoglobin, so as to achieve one or more of the advantagesdescribed herein.

Use of Ultra-Short Pulses:

In accordance with one aspect of an exemplary embodiment of thedisclosure, the system and method of the present disclosure include useof lasers with pulse widths shorter than one nanosecond, especially afew picoseconds or femtoseconds, which promotes treatment as a result ofmore rapid delivery of energy to the desired absorbers within atreatment site.

Super high energy, low power pulses may more effectively disrupt tattooink microspheres than lower energy high power pulses. In other words,picoseconds may be good, but femtoseconds may be better. Depositing allthat energy instantaneously before the molecules can begin losing it asheat assures that the dye spheres will certainly fall apart, allowingthe dye within the treatment site to diffuse into the tissue forintercellular clean up. Since tattoo dyes are complex materials, theenergy also may tend to force them to decompose into smaller and/or morereactive species, which may also promote the clean-up process.

Pilot Study

Results of a pilot study related to the disclosure will be firstreleased publicly in April 2012. The pilot study included tattoo removalwith repeated laser exposures in one session, in which the need for20-minute treatment intervals was eliminated. The pilot study wasconducted at the Laser & Skin Surgery Center of New York (New York,N.Y.), under the direction of Roy G. Geronemus MD.

As background for the pilot study, tattoo removal in a single sessionwith up to four repeated exposures each delivered after resolution ofwhitening had been demonstrated to be more effective than a single passper session. A treatment delay of twenty minutes for resolution ofwhitening limited practicality of the technique, requiring up to eightyminutes of treatment time per visit. Medical grade, sterileperfluorodecalin, an inert, non-toxic liquid fluorocarbon withproperties including optical clarity and gas-carrying capacity, wasevaluated in the pilot study in an effort to speed resolution ofcavitation-induced whitening immediately after laser treatment oftattoos. Perfluorodecalin may increase the optical penetration oflasers.

The pilot study was performed in consenting patients with unwantedtattoos. Each tattoo was treated in whole or part with topicalperfluorodecalin by cotton swab prior to each laser pass. Lasers andsettings were selected by a dermatologist. During and after treatments,extent and duration of whitening reaction was assessed as well asappearance of adverse effects, including pigmentary change or scarring.Each patient was seen at 3-6 weeks for follow-up and possible continuedtreatment.

In fifteen tattoos, perfluorodecalin was applied prior to each laserpass and the tattoo was treated with three Q-switched ruby laser passesimmediately following one another in a single session. In five tattoos,a portion was treated with perfluorodecalin prior to a single pass ofQ-switched ruby or Nd:YAG laser. All tattoos showed immediate whiteningafter laser treatment. After each laser pass, the whitening reactionresolved within five seconds of perfluorodecalin application. Alltreatments were well-tolerated with local anesthesia. Subjects reportednormal to improved healing (amount of blistering, crusting or otherchanges) compared with previous treatments and no adverse effectsoccurred.

It was concluded that topical perfluorodecalin resolves post-laserwhitening within seconds and permits safe immediate sequential treatmentof tattoos in multiple passes (e.g., up to four passes) in a singlesession, allowing more effective tattoo removal in only a few minutes oftreatment time (e.g., about 5 minutes, as compared to about 80 minuteswith R20).

Definitions

The terms used herein and listed below have the meanings indicatedbelow.

The term “HbO₂” means “oxyhemoglobin.”

The term “RHb” means “deoxyhemoglobin.”

The term “metHb” means “methemoglobin.”

The term “NIR” means “near infrared.”

The term “DMSO” means “dimethyl sulfoxide.”

Other Exemplary Embodiments

Certain exemplary embodiments of the disclosure may be described as setforth in the claims below. Of course, the listing below (as well as eachclaim) may be modified in form and content, and the listing is notexhaustive, i.e., additional aspects of the disclosure, as well asadditional embodiments, will be understood and may be set forth andclaimed in view of the description herein. Further, while the inventionmay be susceptible to various modifications and alternative forms,specific embodiments have been shown by way of example in the drawingsand will be described in detail herein. However, it should be understoodthat the invention is not intended to be limited to the particular formsdisclosed. Rather, the invention is to cover all modifications,equivalents and alternatives falling within the spirit and scope of theinvention as defined by the following appended claims.

What is claimed is:
 1. A method comprising promoting opticaleffectiveness before, during, or after at least a portion of a lasertherapy using perfluorodecalin on a skin surface corresponding to atreatment area subject to a laser exposure of the laser therapy, whereinthe laser exposure is capable of directly causing whitening of thetreatment area, and wherein the perfluorodecalin is applied the skinsurface in an amount sufficient to reduce or prevent whitening of thetreatment area to thereby promote optical effectiveness.
 2. The methodof claim 1, wherein promoting optical effectiveness includes reducingwhitening of the treatment area caused by the laser exposure.
 3. Themethod of claim 1, wherein promoting optical effectiveness includespreventing whitening of the treatment area caused by the laser exposure.4. The method of claim 1, wherein promoting optical effectivenessincludes having a time interval between exposure of a region of thetreatment area to a laser output to generate a treated region and asubsequent laser exposure of the treated region effective for the lasertherapy of less than about 20 minutes.
 5. A laser therapy treatmentmethod including a step of providing, in the absence of a chemicalfacilitator that causes a chemical reaction, perfluorodecalin to a skinsurface proximate a treatment area including a benign pigmented lesionbefore, during, or after applying a laser output to the treatment area,wherein the perfluorodecalin inhibits or resolves skin whitening causedby the application of the laser output, wherein the laser output issufficient to cause skin whitening in the absence of theperfluorodecalin.
 6. The method of claim 5, wherein the benign pigmentedlesion is a tattoo.
 7. The method of claim 5, wherein the step includesdelivering perfluorodecalin from a single-patient-use, disposabledevice.
 8. The method of claim 7, wherein the device is a patch.
 9. Themethod of claim 7, wherein the device is a pre-filled applicator. 10.The method of claim 7, wherein the device is a swab.
 11. The method ofclaim 7, wherein the device is sufficiently transparent to the laseroutput so as to enable an amount of laser light of the laser outputeffective for the laser therapy treatment to pass therethrough and tothe treatment area, wherein the laser light that passes through thedevice is sufficient to cause whitening of the treatment area in theabsence of the perfluorodecalin.
 12. A skin treatment method, including:(a) exposing to a laser output a skin portion including a skinpigmentation condition treatable in whole or in part with the laseroutput, wherein the laser output is capable of causing skin whitening;and (b) providing a chemical facilitator to the skin portion, thechemical facilitator consisting essentially of an amount ofperfluorodecalin sufficient to resolve or prevent skin whiteningresulting from step (a).
 13. The method of claim 12, wherein the skinpigmentation condition is a tattoo.
 14. The method of claim 12, furtherincluding: (c) exposing the laser-treated skin portion generated duringstep (a) to a subsequent laser output less than about twenty minutesafter step (a).
 15. The method of claim 12, comprising performing step(c) less than about five minutes after step (a).
 16. A laser treatmentmethod including the step of delivering, in the absence of a chemicalfacilitator that causes a chemical reaction, perfluorodecalin to atreatment site concurrent with a need for the perfluorodecalin, the needbeing indicated by the presence of a pigmented substance at thetreatment site, the treatment site being susceptible to or sufferingfrom skin whitening as a result of laser exposure during the lasertreatment to remove the pigmented substance via photothermolvsis. 17.The method of claim 16, wherein the laser treatment is pulsed lasertherapy capable of causing the skin whitening.
 18. The method of claim16, wherein the step includes delivering the perfluorodecalin from apatch.
 19. The method of claim 18, wherein the patch includes a portionconformable to a portion of a skin surface corresponding to thetreatment site.
 20. The method of claim 18, wherein the patch includes aportion impermeable to perfluorodecalin.
 21. The method of claim 18,wherein the patch includes a portion that enables an amount of laserlight effective for the laser treatment to pass through the patch and tothe treatment site during the laser treatment, wherein the amount oflaser light that passes through the patch is capable of causing skinwhitening.
 22. The method of claim 16, wherein the step includesdelivering the perfluorodecalin from a patch, and wherein the patchreduces ejecta proximate the treatment site.
 23. A method comprisingtreating a skin region suffering from or susceptible to whitening causedby non-low level laser therapy during removal of a benign pigmented skinlesion by delivering, in the absence of a chemical facilitator thatcauses a chemical reaction, perfluorodecalin to the skin region using apatch.
 24. The method of claim 23, wherein the perfluorodecalin resolvesthe whitening thereby making the skin region more receptive to a non-lowlevel laser output of the non-low level laser therapy to facilitateremoval of the benign pigmented skin lesion.
 25. The method of claim 24,wherein the perfluorodecalin resolves the whitening in less than 20minutes.
 26. The method of claim 23, comprising placing a side of thepatch having the perfluorodecalin against a skin surface correspondingto the skin region to deliver the perfluorodecalin to the skin region.27. The method of claim 23, comprising exposing the skin region to anon-low level laser output through the patch in an amount effective tocause photothermolysis for removal of the benign pigmented skin lesion.